US stocks fell across the board Monday, with chipmakers taking the worst hit — bad news for anyone holding AI and semiconductor shares, including TSMC.

• Anthropic's Anthony Amodei called for AI companies to slow down work on the most advanced models to reduce the risk of AI slipping out of human control, and OpenAI's Sam Altman and Elon Musk backed the idea.
• Investors read that as a threat to data center building and AI spending, and chip and memory stocks were hammered — the Philadelphia semiconductor index dropped almost 6% and TSMC's US-listed shares fell over 3%.
• Trump attacked the slowdown push, warning that holding back American AI only helps China.
• Oil kept climbing after Saudi Arabia shut a pipeline that bypasses the Strait of Hormuz and fighting in the Middle East widened, with US crude above $100 a barrel.
• Government bond yields briefly broke 5% for the first time since late 2023, and traders now see a Fed rate hike this week as nearly certain.

Outlook: A near-certain rate hike, $100 oil, and doubts about AI spending leave stocks — especially chipmakers — exposed to more selling in the days ahead.